Will the arrival of his old flame force Holby City's Hanssen to face up to his responsibilities? Guy Henry reveals more about Tuesday's episode on BBC1...
Hanssen's old flame Maja turns up at Holby this week. What's the history between them?
"Hanssen had abandoned Maja 25 years earlier when she was pregnant. Back then, Hanssen felt unable to offer what she and the baby would deserve which would be his love and commitment, so he thought it better to leave them to get on with their lives, without what he saw as his destructive influence."
Hanssen was reunited with Maja earlier this year when he went over to Sweden. How were things left between them?
"Hanssen apologised for leaving them and Maja offered him the chance to meet his son, named Frederik. But he didn't have the courage and ran straight back to Holby and to the safety of his work and the life he knows."
So how does Hanssen react when he sees Maja at the hospital?
"Well, he's expecting another professor from Sweden, who's coming to England to watch an NHS hopital at work, and suddenly there's Maja on the ward, so obviously he's very shocked.
Hanssen tries to avoid Maja throughout the day and gets very angry when she suggests they have dinner that evening. How does she provoke such a reaction?
"Well, Hanssen and Maja loved each other once. So she really gets under his skin and reaches parts of him other people can't."
Maja sees Hanssen's softer side when he helps young doc Arthur Digby with a complicated procedure in theatre. Does he really have a caring side?
"Yes, I think he does. Hanssen's always encouraged talent - Arthur is this wonderful, geeky, neurotic young man and I think Hanssen sees similarities with himself. But, in his heart of hearts, Hanssen knows this is just a substitute and that he's missing out on nurturing a son of his own."
We discover that this is in fact why Maja has come to Holby - to give Hanssen another chance to see his own son...
"Maja shows Hanssen a photo of his son Frederik, who's now a grown man, and his pregnant girlfriend and to see a photo of his own son is so moving for him. But Hanssen still puts up this wall of ice as a way of closing himself off from feeling that might hurt himself."
Do you think Hanssen will ever reunite with his son?
"I don't think the subject is closed but, at the moment, he can't make that journey towards being a father."
Do you enjoy showing the chinks in Hanssen's armour?
"Yes, there's obviously a vulnerable side to him and I'm glad the writers are keen to investigate what's going on in his strange, muddled mind. Hanssen's always been a fantastic character to play - he's an extraordinary, weird man. Weird and sort of wonderful!"
